WEST PALM BEACH — Nancy Salmi moved to Century Village in suburban West Palm from California’s high desert in 2004, to be near her son and grandchildren, who live in Wellington.

In the sprawling, 55-and-older community of two-story condos, Salmi, who uses a walker, found a ground-floor unit condo for $35,000. The 71-year-old with shoulder-length gray hair and a sunny disposition still loves the 615-square-foot, one-bedroom unit in the Sheffield O building.

But now she lives under a cloud. An investor has snapped up most of the building and wants to force the other owners out.

“I am in the process of taking steps to dissolve the Association of Sheffield O whereby all of the apartments that I do not own would be forced to sell to me at the Palm Beach County Appraisers value,” Donald T. Kelly, wrote to Sal-mi on March 2.

Whether he can do so is not clear, said Dave Israel, president of United Civic Organization, the coordinating authority for Century Village’s 309 property owners associations. What is clear, Israel says: The entire community is in a panic over whether what happens at Sheffield O could topple other buildings like dominoes.

“These are elderly people, and they’re scared to death,” he said.

Kelly has not revealed his plans for Sheffield O or other buildings where he has been accumulating condos for the past four years. The Palm Beach Gardens resident said that on the advice of his lawyer, he would not talk. The word in the community at various times has been that he might turn the building into an assisted-living facility or a rehab center or just rent out the condos. Residents say he already rents some units to people directed there by a nonprofit that helps the homeless transition into housing.

According to Israel, Florida law allows investors who own 80 percent of a building’s condos to force the remaining 20 percent to sell. By his count, Kelly owns 15 units of the building’s 26 condos, some under the name of trusts he controls and has the power of attorney over two others.

“That gives you control of 17,” Israel said. “The magic number to dissolve a condominium association to buy out the rest under the current statute is 80 percent, “which would require him to own 21 condos.

Kelly already is president of the Sheffield O Condominium Association.